No more magic numbers for your breakpoints

Using CSS container queries with the `ch` unit instead of arbitrary pixel or rem values creates content-aware breakpoints. When a three-column layout is set to break at 90ch, each column is roughly 30 characters wide — aligning with minimum readable line-length guidelines. Unlike media queries, container queries respect the element's own font size, so breakpoints adapt automatically when the base font size changes. This approach replaces magic numbers with meaningful, content-first breakpoints.